Impressions: The number of times tweets sent as a result of a specific episode are seen, as measured by Twitter. It's important to point out this is not a "potential impressions" number based on follower counts. Twitter is able to track which tweets appear both on the screen of mobile devices and which batches are loaded for users online. Example: There were 15,700,400 impressesions as a result of the Oct. 5 SNL episode.

Unique audience: The total number of accounts that view at least one tweet pertaining to a specific episode. Again, Twitter provides this data, with the ability to monitor what tweets are viewed on various platforms. Example: 3,146,500 individual accounts saw at least one tweet about the Oct. 5 SNL episode.

The introduction of the Nielsen Twitter TV Ratings comes as a result of a dramatic increase in real-time tweeting during television viewing. About 19 million people composed approximately 263 million tweets about live TV, not including sports, in Q2 of 2013, according to SocialGuide, which works with Nielsen to publish the ratings.

How the new ratings affect strategy moving forward remains to be seen.

Will shows prioritize viewers to tweet during the show? Will they create plots specifically to engage users?

To what degree advertisers place emphasis on a strong Nielsen Twitter TV Rating will likely answer those questions.

The first batch of ratings comes four days after the San Francisco-based company announced on its own Twitter feed -- @Twitter -- it was filing S-1.